The invention provides a method for treating a medical condition, disease, or disorder mediated by a misfolded form of superoxide dismutase (SOD) in a subject in need of treatment. The method optionally comprises administering to the subject a composition comprising a pharmaceutically acceptable vehicle and an agent selected from (1) an exogenous antibody or fragment thereof that binds selectively to the misfolded form of SOD, and/or (2) an immunogen that elicits production of an endogenous antibody that binds selectively to the misfolded form of SOD, and/or (3) a nucleic acid sequence encoding (1) or (2). In certain embodiments, the invention provides methods of treating diseases such as Alzheimer's Disease, Parkinson's Disease or amyotrophic lateral sclerosis using amyotrophic disease-specific epitopes, and compositions including these epitopes. The invention also provides antibodies that bind to monomeric or misfolded SOD1, and not on the molecular surface of native homodimeric SOD1. In addition, the invention includes methods of diagnosing Alzheimer's Disease, Parkinson's Disease or amyotrophic lateral sclerosis in a subject. Also, the invention provides methods of identifying substances for the treatment or prevention of Alzheimer's Disease, Parkinson's Disease or amyotrophic lateral sclerosis and kits using the binding proteins of the invention.